This short wartime documentary describes Canada’s airmail service in 1944. Every night, Trans-Canada Airlines Flight 6 crossed Canada from Vancouver to Montreal with its load of blue and yellow airmail bags, playing an important role in Canadian life and business. Three times a week, cargoes bound eventually for London, Moscow, Lisbon and Paris were flown to Scotland. Letters and parcels for prisoners of war, diplomats, business executives and soldiers went into a thirty-ton Lancaster. When decisions were vital and information had to travel quickly, Canada's air service proved its value.